During orthopedic knee arthroplasties, the worn out bone and cartilage is removed and replaced with various biocompatible implants to take the place of the resected bone and cartilage. Knee arthroplasty usually includes a femoral component that is fixed onto a distal end of a femur, and tibial components that include a tibial tray and an intermediate component. To affix these components to the bone, a series of cuts are made to the distal end of the femur and a proximal end of the tibia. To make these cuts in the bones, surgeons use a variety of cut guides that are used to guide a blade of a bone saw through the bones of the patient.
Many modern orthopedic knee arthroplasties use computer assistance to help the surgeon perform an accurate and replicable surgery. Currently, “navigation” systems are used for the computer to register the bone. These systems are able to help verify and estimate a general surface of the bone through a probing sequence that is timely and cumbersome for surgeons. After the bone is registered, it is required during knee arthroplasties that mechanical axes of the leg are discovered to be able to make the distal cut to the femur perpendicular to the axes. Many systems use an intramedullary rod and/or an extramedullary rod, while others use contact infrared probes.
Therefore, there is a need for a system that is able to accurately register the bone in real time, calculate the mechanical axes of the leg without probes, and be able to guide the surgeon to accurately place the implant/prosthesis through a real time measurement array.